Turkish oil refiner TUPRAS named biggest firm

According to the survey, TUPRAS' production-based sales last year totalled 51.1 billion Turkish liras ($14 billion).

International car manufacturer Ford was the second-biggest company with production-based sales of 22.7 billion liras ($6.2 billion), followed by automaker Toyota in third with 17.8 billion liras ($4.9 billion).

The survey said the total production-based sales of industry giants posted their highest growth in 13 years, up 33.2 percent year-on-year, to reach 653 billion liras ($178.9 billion).

The growth stemmed from the hike in exchange rates, which plays an important role in export revenues, along with growing domestic and foreign demand.

Last year, one U.S. dollar traded for 3.65 Turkish liras on average, compared to 3.02 in 2016.

ISO 500 companies’ exports surged 17 percent last year to $64.5 billion, making up 42.8 percent of Turkey's total industrial exports.

Financial expenses accounted for more than half of the operating profit of industrial enterprises, it said.

The ISO has been announcing data on Turkey’s top 500 companies since 1968.